===================================================== BUG: KMSAN: uninit-value in sctp_inq_pop+0x14dc/0x19e0 net/sctp/inqueue.c:211 sctp_inq_pop+0x14dc/0x19e0 net/sctp/inqueue.c:211 sctp_assoc_bh_rcv+0x1a0/0xbc0 net/sctp/associola.c:980 sctp_inq_push+0x2a3/0x350 net/sctp/inqueue.c:88 sctp_backlog_rcv+0x3c7/0xda0 net/sctp/input.c:331 sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148 __release_sock+0x1d3/0x330 net/core/sock.c:3213 release_sock+0x6b/0x270 net/core/sock.c:3767 sctp_wait_for_connect+0x458/0x820 net/sctp/socket.c:9367 sctp_sendmsg_to_asoc+0x223a/0x2260 net/sctp/socket.c:1886 sctp_sendmsg+0x3910/0x49f0 net/sctp/socket.c:2032 inet_sendmsg+0x269/0x2a0 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x278/0x3d0 net/socket.c:727 __sys_sendto+0x593/0x720 net/socket.c:2180 __do_sys_sendto net/socket.c:2187 [inline] __se_sys_sendto net/socket.c:2183 [inline] __ia32_sys_sendto+0x12f/0x200 net/socket.c:2183 ia32_sys_call+0x1397/0x42c0 arch/x86/include/generated/asm/syscalls_32.h:370 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb0/0x150 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x38/0x80 arch/x86/entry/syscall_32.c:331 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:369 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Uninit was stored to memory at: ------------[ cut here ]------------ WARNING: CPU: 1 PID: 12730 at kernel/stacktrace.c:29 stack_trace_print+0xd4/0xf0 kernel/stacktrace.c:29 Modules linked in: CPU: 1 UID: 0 PID: 12730 Comm: syz.0.2417 Tainted: G W 6.16.0-rc7-syzkaller-00140-gec2df4364666 #0 PREEMPT(none) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:stack_trace_print+0xd4/0xf0 kernel/stacktrace.c:29 Code: 28 40 03 92 89 de ba 20 00 00 00 4c 89 e1 e8 c3 71 4d ff 49 83 c6 08 49 ff cd 0f 85 6e ff ff ff eb 0b e8 ef 50 c1 00 eb d4 90 <0f> 0b 90 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 66 0f 1f RSP: 0018:ffff888036af70a8 EFLAGS: 00010246 RAX: ffff888045a44cd8 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888036af70d0 R08: 0000000000000000 R09: 0000000000000000 R10: ffff8880362f70e8 R11: ffffffffffff1298 R12: 0000000000000000 R13: 00000000abcd0100 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881aa962000(0063) knlGS:00000000f50e6b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f72238a0 CR3: 000000003bfd8000 CR4: 00000000003526f0 Call Trace: kmsan_print_origin+0xb0/0x340 mm/kmsan/report.c:133 kmsan_report+0x1d3/0x320 mm/kmsan/report.c:196 __msan_warning+0x1b/0x30 mm/kmsan/instrumentation.c:315 sctp_inq_pop+0x14dc/0x19e0 net/sctp/inqueue.c:211 sctp_assoc_bh_rcv+0x1a0/0xbc0 net/sctp/associola.c:980 sctp_inq_push+0x2a3/0x350 net/sctp/inqueue.c:88 sctp_backlog_rcv+0x3c7/0xda0 net/sctp/input.c:331 sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148 __release_sock+0x1d3/0x330 net/core/sock.c:3213 release_sock+0x6b/0x270 net/core/sock.c:3767 sctp_wait_for_connect+0x458/0x820 net/sctp/socket.c:9367 sctp_sendmsg_to_asoc+0x223a/0x2260 net/sctp/socket.c:1886 sctp_sendmsg+0x3910/0x49f0 net/sctp/socket.c:2032 inet_sendmsg+0x269/0x2a0 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x278/0x3d0 net/socket.c:727 __sys_sendto+0x593/0x720 net/socket.c:2180 __do_sys_sendto net/socket.c:2187 [inline] __se_sys_sendto net/socket.c:2183 [inline] __ia32_sys_sendto+0x12f/0x200 net/socket.c:2183 ia32_sys_call+0x1397/0x42c0 arch/x86/include/generated/asm/syscalls_32.h:370 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb0/0x150 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x38/0x80 arch/x86/entry/syscall_32.c:331 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:369 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7fc5539 Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f50e655c EFLAGS: 00000206 ORIG_RAX: 0000000000000171 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080847fff RDX: 000000000000fee4 RSI: 0000000000000000 RDI: 000000008005ffe4 RBP: 000000000000001c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---[ end trace 0000000000000000 ]--- Uninit was created at: slab_post_alloc_hook mm/slub.c:4154 [inline] slab_alloc_node mm/slub.c:4197 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_node_track_caller_noprof+0x96d/0x12f0 mm/slub.c:4347 kmalloc_reserve+0x22f/0x4b0 net/core/skbuff.c:601 __alloc_skb+0x347/0x7d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1336 [inline] sctp_packet_pack net/sctp/output.c:472 [inline] sctp_packet_transmit+0x18a1/0x46d0 net/sctp/output.c:621 sctp_outq_flush_transports net/sctp/outqueue.c:1173 [inline] sctp_outq_flush+0x1c7d/0x67c0 net/sctp/outqueue.c:1221 sctp_outq_uncork+0x9e/0xc0 net/sctp/outqueue.c:764 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:-1 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1204 [inline] sctp_do_sm+0x8c8e/0x9720 net/sctp/sm_sideeffect.c:1175 sctp_assoc_bh_rcv+0x88b/0xbc0 net/sctp/associola.c:1034 sctp_inq_push+0x2a3/0x350 net/sctp/inqueue.c:88 sctp_backlog_rcv+0x3c7/0xda0 net/sctp/input.c:331 sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148 __release_sock+0x1d3/0x330 net/core/sock.c:3213 release_sock+0x6b/0x270 net/core/sock.c:3767 sctp_wait_for_connect+0x458/0x820 net/sctp/socket.c:9367 sctp_sendmsg_to_asoc+0x223a/0x2260 net/sctp/socket.c:1886 sctp_sendmsg+0x3910/0x49f0 net/sctp/socket.c:2032 inet_sendmsg+0x269/0x2a0 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x278/0x3d0 net/socket.c:727 __sys_sendto+0x593/0x720 net/socket.c:2180 __do_sys_sendto net/socket.c:2187 [inline] __se_sys_sendto net/socket.c:2183 [inline] __ia32_sys_sendto+0x12f/0x200 net/socket.c:2183 ia32_sys_call+0x1397/0x42c0 arch/x86/include/generated/asm/syscalls_32.h:370 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb0/0x150 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x38/0x80 arch/x86/entry/syscall_32.c:331 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:369 entry_SYSENTER_compat_after_hwframe+0x84/0x8e CPU: 1 UID: 0 PID: 12730 Comm: syz.0.2417 Tainted: G W 6.16.0-rc7-syzkaller-00140-gec2df4364666 #0 PREEMPT(none) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 ===================================================== ---------------- Code disassembly (best guess): 0: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 4: 10 07 adc %al,(%rdi) 6: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi a: 10 08 adc %cl,(%rax) c: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 20: 00 51 52 add %dl,0x52(%rcx) 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 ret 2e: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 90 nop 33: 90 nop 34: 90 nop 35: 90 nop 36: 90 nop 37: 90 nop 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop